Crystal structures of two new isocoumarin derivatives: 8-amino-6-methyl-3,4-diphenyl-1H-isochromen-1-one and 8-amino-3,4-diethyl-6-methyl-1H-isochromen-1-one.

The title compounds, 8-amino-6-methyl-3,4-diphenyl-1H-isochromen-1-one, C(22)H(17)NO(2), (I), and 8-amino-3,4-diethyl-6-methyl-1H-isochromen-1-one, C(14)H(17)NO(2), (II), are new isocoumarin derivatives in which the isochromene ring systems are planar. Compound II crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. In I, the two phenyl rings are inclined to each other by 56.41†(7)° and to the mean plane of the 1H-isochromene ring system by 67.64†(6) and 44.92†(6)°. In both compounds, there is an intra-molecular N-H⋯O hydrogen bond present forming an S(6) ring motif. In the crystal of I, mol-ecules are linked by N-H⋯π inter-actions, forming chains along the b-axis direction. A C-H⋯π inter-action links the chains to form layers parallel to (100). The layers are then linked by a second C-H⋯π inter-action, forming a three-dimensional structure. In the crystal of II, the two independent mol-ecules (A and B) are linked by N-H⋯O hydrogen bonds, forming -A-B-A-B- chains along the [101] direction. The chains are linked into ribbons by C-H⋯π inter-actions involving inversion-related A mol-ecules. The latter are linked by offset π-π inter-actions [inter-centroid distances vary from 3.506†(1) to 3.870†(2)†à ], forming a three-dimensional structure.